GB-4
D
GB
F
NL
I
E
Changing the outlet pressure p
a
▷
▷
The outlet pressure p
a
is set at the factory with
the spring dome pointing vertically upwards. If
the VGBF is installed with the spring dome in the
horizontal position, check and adjust the outlet
pressure p
a
.
▷
▷
Use the test points on the unit only for measure-
ments of zero flow or very slight flow.
− +
0
p
a
6 mm
2
1
4
3
5
Clearly mark the adjusted value of the outlet pres-
sure p
a
on the type label.
Maintenance
In order to ensure smooth operation: check the func-
tion annually, or every six months if operated with
biologically produced methane.
1
Request different outputs on the burner in order
to change the flow rate.
2
Close the manual valve at the inlet a little in order
to change the inlet pressure p
e
.
▷
▷
Despite changing flow rates and inlet pressures p
e
(within the capacity range of the VGBF), the outlet
pressure p
a
must remain constant (± 10 – 15%).
Reduce the capacity to low-fire rate and close
the valve downstream of the VGBF.
▷
▷
Approx. 30 seconds after the valve has been
closed, the outlet pressure p
a
should not increase
significantly.
Check the tightness of the VGBF during operation
to detect possible leaks due to hardened rubber
materials.
5
4
6
If a leak is found, replace the rubber materials –
see spare parts DVD, “PartDetective”.
7
Then check for tightness once again.
Replacing the spring
1
Choose a spring according to the outlet pressure
range (see [Spring table – p. 6]).
2
Remove the cover cap.
WARNING
The taut spring can pop out when opening the
spring dome and lead to injury. Therefore, decom-
press the spring as far as it will go before open-
ing. Then turn back 5 × to relax the spring counter
bearing.
6 mm
5x
5
3
4
7
8
6
VGBF 15 – 50
9
Turn down the spring counter bearing slightly.
10
11
12
Ensure that the guide grooves and bars engage
in each other.
VGBF 65 – 150
9
Turn down the spring counter bearing slightly.
10
11
12
Ensure that the guide groove and the cylinder
engage in each other.
VGBF 15 – 150
− +
0
p
a
6 mm
14
13
15
Screw on cover cap.
16
After inserting the spring, take the spring’s label
from the packaging and stick it below the type
label on the pressure regulator.
17
Clearly mark the adjusted value of the outlet pres-
sure p
a
on the type label.
